What is Grevillea?
Grevillea (Grevillea robusta), also known as silk oak, is a tree from the Proteaceae family. It originated in Australia, but is now growing well in North America. This is a tall tree and is referred to as being a skyline tree with lots of vertical accent. Grevillea is very fast growing and can live 50 to 65 years. This evergreen has a rugged look. It can grow to be over 100 feet (30 m.) tall, but most mature trees are around 50 to 80 feet (15-24 m.) high and 25 feet (8 m.) wide. Although the tree is tall, the wood is very brittle and the top branches are known to blow off in heavy winds. However, the wood is often used for lumber for cabinet making. The leaves of the tree look like the foliage of a fern, with feathery leaves. In the spring it blooms with bright yellow and orange flowers. After the tree is done blooming, it reveals black leather-like seed pods. Birds and bees love the tree’s nectar and are always around it. Unfortunately, Grevillea can be messy to clean up when leaves and flowers drop, but the beauty is well worth it.
How to Grow Grevilleas
Since Grevillea is tall, wide, messy, and the branches fall off commonly, it does best in an open area away from buildings and roads. Grevillea also grows best in USDA zones 9-11 and prefers well-drained soil to prevent root rot. Growing Grevillea in the garden in these zones is not difficult. It is fairly drought resistant and likes to have full sun. This tree seems to do well in southern Florida, Texas, California, and New Mexico. For not living in a suitable growing zone, this plant can also be grown in containers and kept indoors. Plant Grevillea in a suitable location, allowing plenty of room for the tree to spread. Dig a hole that is twice the width of the rootball and deep enough to accommodate the young tree. Water immediately after planting.
Grevillea Plant Care
This tree is hardy and doesn’t require much care, although it may need water when young to help get it established. The canopy base may need to be trimmed occasionally to allow for more growth, but this is usually not a problem. Caterpillars can sometimes harm the tree and should be eliminated if possible.
